1. Field of the Invention
The invention relates to the field of digital computer compliers particularly compilers used in the evaluation of Boolean or like expressions, and a computer for executing a program compiled in accordance with the present invention.
2. Prior Art
The present invention was developed to provide more efficient evaluation of Boolean expressions associated with ladder structures. The invention is particularly useful in evaluating ladder rungs having logic elements such as are evaluated in programmable controllers. The prior art technique for evaluating such ladder structures is described within the detailed description of the invention. The advantages gained with the invented compiler when compared to this prior art technique are also discussed. As will be seen, in the prior art an interpreter was employed to interpret source code instructions. With the present invention, an intelligent compiler provides an object code program which is directly executed. The state of the elements drives the branching used in the object code program.
The Applicant is not aware of any prior art compilers using the invented method, nor is the Applicant aware of any computers such as the one described.